A walker with wheels (i.e. rollator, or rolling walker) has become increasingly more popular. For example, U.S. Pat. Nos. 4,907,794 and 5,020,560 disclose a foldable rolling walker. Consequently, a braking system is needed to stop the wheels. However, such braking system is a temporally braking device which is similar to that of a bicycle, i.e. a braking effect is actuated only when a user pulls up the braking handle.
U.S. Pat. No. 5,279,180 (Henriksson) discloses a braking system which can be operated in two ways, i.e. temporally and continuously braking status. When a user pushes an operative arm of downward, by utilizing the "locking force", the operative arm is maintained in a continuously locking position. Therefore, when the user releases the operative arm, for example, the wheels of a rolling walker are still braked. However, the "locking force" must be larger than the returning force of the releasing spring installed in the braking system, which may causes the following disadvantages:
1. The locking engagement between an operative arm and a bracket is affected by an interference fit therebetween and, as a result, after a period of usage, the contacting area will be worn out and the "locking force" will be diminished.
2. Because the "locking force" is larger than the returning force of the releasing spring, the force of pushing the operative arm of downward, therefore, must larger than the returning force of the releasing spring. The pushing force will hasten the deterioration of the contacting area of the operative arm and the bracket.